LPR scenario emphasizing the putative regulatory roles of basophils in allergic inflammation.

Eotaxin (CCL11) (A) derived from epithelial cells,184eosinophils,51 or mast cells185 can be detected in the lungs of asthmatic patients50-53 and recruits cells expressing the eotaxin receptor (CCR3), ie, eosinophils,186,187 basophils,10,55 Th2 cells,188,189 and mast cells.190,191Recruited basophils are a major source of the regulatory cytokines IL-43,4 and IL-13.5-7 There are several potential amplification loops, such as the up-regulation of eotaxin in airway epithelial cells97 (B) and VCAM-1 on vascular endothelium (C) by IL-1396 or IL-442 or, also, the up-regulation of eotaxin by IL-4 in fibroblasts.90Eotaxin has also been shown to potentiate the IL-4 production by activated basophils91 (D). Furthermore, basophils can deliver the signals necessary for switching B cells to IgE (E), ie, IL-4, IL-13, and CD40L.8,9 The increased IgE production is thought to up-regulate the expression of FcεRI on basophils and mast cells103,104 (F).